Yep - it's one of those features that you need multiple times a day, but Microsoft didn't manage to create a direct shortcut for it! Of course they did have time to come up with a shortcut to display the Research task pane (ALT+SHFT+F7) - that thing you didn't even know existed.

Anyway the good news is they did include the next-best thing - a shortcut to paste special. It's CTRL-ALT-v. From there you can reasonably painlessly arrow to the "plain text" option and hit return.

I think the Free Software Foundation (FSF) has hijacked the word "free". To most people "free" means without cost. Of course in English it has a number of other meanings, for example a seat can be free. However the FSF uses the word to describe a restrictive form of licence that ensures that any person that comes into posession of such licenced software is free to do with it anything that the FSF thinks would be good.